Scrapers for tubular strings



1965 A. w. KAMMERER, JR 3,199,599

SCRAPERS FOR TUBULAR STRINGS 2 Sheets-Sheet 1 Filed Aug. 20, 1962INVENTOR. JQQCHEE H Z' KHMMEZQEE, rle.

flTTOQA/EYS.

1955 A. w. KAMMERER, JR 3,199,599

SCRAPERS FOR TUBULAR STRINGS 2 Sheets-Sheet 2 Filed Aug. 20, 1962INVENTOR. flea/E2 u: Ham/45252, rle.

firraeusys.

United States Patent Office 3,199,599 Fatented'Aug. 10, 1965 3,199,599SCRAPERS FGR TUBULAR STRINGS Archer W. Karnmerer, in, Houston, Tex.,assrgnor to Bakers Oil Tools, Inc., Los Angeles, Calif., a corporationof California Filed Aug. 29, 1962, 'Ser. No. 218,000 16 Claims. (Cl.166-173) The present invention relates to subsurface well boreequipment, and more particularly to scrapers for removing substancesfrom the inner Walls of tubular strmgs disposed in well bores, such ascoatings of drilling mud, cement, rust, mill scale, paraffin, andembedded bullets, and burrs formed by bullets fired through the tubularstrings.

An object of the present invention is to provide a scraper for use intubular strings, which is of strong and sturdy construction, economicalto manufacture, possessed of relatively few parts, and relatively easyto assemble and disassemble.

Another object of the invention is to provide a scraper for use intubular strings of relatively small diameters, such as in tubingdisposed in a well bore, the scraper having considerable strengthdespite its small size, and well able to withstand safely extreme loadsto which it might be subjected.

A further object of the invention is to provide a scraper for use in atubular strin which has laterally shiftable cutter members that cancollectively cover the 360 degree circumference of the inner wall of thetubular string, allowin the scraper to clean the entire circumference ofthe tubular string as a result of moving the scraper longitudinallytherethrough, and which is also effective in cleaning the inner wall ofthe tubular string upon rotation of the scraper, there being largebearing areas for transmitting torque and longinidinal thrusts from themain body of the scraper tool to the cutter members mounted thereon.Such large bearing areas are present and the body of the tool has greatstrength despite the making of the tool of small size for operating inrelatively small diameter tubular strings, such as tubing strings.

An additional object of the invention is to provide a scraper forcleaning the inner wall of a tubular string disposed in a well bore andthrough which circulating fluid can be pumped, in which such fluid isprevented from eroding or fluid cutting the main body of the scraper.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the present specification. It will nowbe described in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a side elevational view of a scraper disposed in a tubularstring;

FIG. 2 is an enlarged side elevational view of a portion of the scraperillustrated in FIG. 1;

FIG. 3 is an enlarged cross-section taken along the line 33 on FIG. 1;

FIG. 4 is an enlarged longitudinal section taken along the line 44 onFIG. 1; 7

FIG. 5 is a cross-section taken along the line 55 on FIG. 4, but rotated90 degrees relative to the position illustrated in FIG. 4;

FIG. 6 is a side elevation of one of the scraper blades;

FIG. 7 is a rear elevation of one of the scraper blades, as seen fromthe left of FIG. 6;

FIG. 8 is a cross-section taken along the line 88 on FIG. 7.

The scraper A illustrated in the drawings is designed to clean the innerwall of a tubular string B, such as a string of tubing, disposed in awell bore C. The scraper includes a generally cylindrical, elongate body10 having an upper threaded pin 12 for securing the body of the lowerend 13 of a running-in string D, such as a tubular string, which lowerend may be constituted as a coupling. The lower end of the body 10 maybe constituted as a threaded pin 14 thereon for attachment to a lowertubing section (not shown), which may, in turn, be secured to a rotarydrill bit (not shown).

The cylindrical body of the tool has a central passage 15 extendingcompletely therethrough, as well as longitudinally spaced lateral slots16 which are angularly displaced or out of phase with one anothercircumferentially of thebody of the tool.' Each slot 16 extends from theperiphery of the body at one side thereof through the diametricallyopposite side, and also intersects the passage 15 through the tool. Eachslot has parallel side walls 17 and parallel top and bottom walls 18, 19normal thereto, there being diametrically opposite scraper blades orcutters 20 mounted in each slot and having external scraper teeth 21 foroperation upon the inner wall of the tubular string B. These teeth 21are curved to conform substantially to the inner wall of the tubularstring when engaged therewith. The teeth 21 on the exterior of eachscraper blade 21' are longitudinally spaced from each other and areinclined or helical, the lower edge 22 of each tooth being suitablyhardfaced so as to enhance its wear resistance.

Each blade has parallel side walls 23 slidable along the side walls 17of the slot and also top and bottom walls 24, 25 slidable along the topand bottom walls 18, 19 that define each slot. T o prevent each blade 29from being mounted in its slot 16 in an inverted position, the lower endof each blade may be formed with a relatively small downward projection26 slidably fitting Within a central radial groove 27 opening into thebottom 19 0f the slot.

The width of each slot 16 is substantially greater than the diameter ofthe central passage 15 through the body 10 of the tool. To allowdrilling fluid to be pumped down through the device for continued flowto a lower tool, such as a drill bit (not shown), a central tubularmember or wash pipe 28 is inserted in the central passage 15, extendingsubstantially from its top to its bottom end-s. Leakage of fluid betweenthe wash pipe and the wall of the body passage 15 is prevented bysuitable upper and lower seals rings 29, such as rubber or rubber-like 0rings, disposed in internal grooves 30 in the tool body 10 and engagingthe periphery of the wash pipe 28. The lower end of the wash pipe ortubular member engages a spacer ring 31 disposed in a counterbore 32 in.the lower pin end 14 of the body, the spacer ring being held in place bya split, snap retainer ring 33 overlying the lower end of the spacerring and disposed within an intern-a1 groove 34 in the body. Similarly,a spacer ring 35 overlies the upper end of the tubular member 28, beingdisposed in a counterbore 36 in its upper portion and held in place by asplit, snap retainer ring 37 disposed within an internal groove 38 inthe upper portion 12 of thebody and overlying the spacer ring 35. Byrelmovin-g one or 'both of the retainer rings 33, 37, as a result ofretracting them inwardly from their respective grooves 34, 33, a spacerring 31 or 35 can be rernoved and the tubular member or 'Was'h pipe 28taken from the central passage '15 of the body 10.

The tubular member-0r circulation tube 28 is easily mounted in the 'body'10 of the tool. Since it is a part separate from the tool body 10, itcan be made of a '13 harder material and more resist-ant to fluidcutting or the erosive action of the drilling mud, or other fluid, beingpumped down through the tubular string D or drill pipe, or the like, andthrough the tube 23. Thus, the circulating fluid does not act on theinterior of the tool body at all, resulting in the body having :a muchlonger life. In the event that substantial wear does occur on thecirculation tube 28, it is easily replaced without the necessity forreplacing the entire body 10.

For the purpose of increasing the bearing area between the sides 23 ofeach blade and the companion adjacent sides 17 of each slot 16, theinner portion of each blade is made concaved or recessed along itsentire longitudinal extent, so as to allow'the blade to extend inwardlyof the slot 16 and around the wash pipe 23, the latter being receivedwithin the longitudinal blade recess 40, :as disclosed in the drawings.Thus, there is a greater side area on each blade 29) engaging thecompanion side 17 of the body slot for the transmission of torque duringrotation of the tool in effecting the scraping of the inner wall of thetubular string B.

The diametrically opposed blades 26 each constitute a set, and each setof blades is urged in opposite directions outwardly of the body lil by aspring device. As disclosed, a row of longitudinally spaced helicalsprings 41 is provided on each side of the wash pipe 23, engaginginwardly directed flanges 42 of the opposed scraper blades 20, eachspring extending between and engaging the flanges 42 of the opposedblades and urging the blades outwardly. To insure the retention of thesprings 41 in appropriate assembled position, their end portions aredisposed in spring sockets 43 formed in the side portions or bladeflanges 42, the springs bearing against the base or inner ends of thesockets. The force provided by the sets of longitudinally spacedlaterally extending springs 41 on opposite sides of the wash pipe 28against the blades 20 can be quite substantial, pressing the blade teeth21 against the wall of the tubing B.

The blades can shift inwardly of its slot 15 against the force exertedby the springs 41. The extent of shifting of each blade outwardly of'thebody is limited by a suitable stop device. As shown, there is anenlarged transverse opening extending through each blade through which astop element, such as the shank 51 of a stop screw 52, extends, thisshank having a much smaller diameter than the diameter of the opening59. The head 53 of the stop screw is disposed in a suitable externalbody recess 54 so as to lie within the periphery of the body 10, thishead bearing against a suitable lock washer 55 engaging the base of therecess 54. The opposite end 55 of the screw is threaded and isthreadedly received within a companion threaded bore 57 in the body 10of the tool. By suitable tightening of the screw 52, it will remainattached to the tool body 110, extending through the enlarged opening50. When the tool A is out of the tubular string B, the spring 41 canonly expand the cutter blades 20 outwardly of the periphery of the bodyto the extent determined by engagement of the inner portions of eachblade, which, as shown, are the flange portions 42, with the stop screw52.

As illustrated in the drawings by way of example, the tool A has threesets of scraper blades 20 disposed in three slots 16 extendingcompletely through the body 10 of the tool and intersecting its centralpassage 15. The body slots 16 receiving the sets of cutter blades aredisposed progressively out of phase with one another, so that thecuttter blades 20 disposed in the slots and their teeth 21 collectivelycover the entire circumference of the inner wall of the tubular'string Bin which the tool is disposed. Wit-h the three sets of bladesspecifically shown in the drawingsfthe progressive displacement of eachset of blades, from the upper to the lower set, about 60 'degress fromone another, with the cutter teeth 21 on each blade covering about 60degree of arc, will result in all of the cuttters 20 collectivelycovering the entire circumference of the inner wall of the tubularstring B in which the scraper is being operated.

The scraper can be attached to a string of drill pipe D, or the like,and lowered in the well tubing B. The mere movement of the scraperlongitudinally through the tubing, without rotation, will cause itsinclined helical teeth 21 to scrape the entire circumference of thetubular string B. If desired, the drill pipe D and tool A can berotated, and because of the inclination of the teeth 21, the wall of thetubular string will also be scraped to remove foreign substancestherefrom, effecting it thorough cleaning. During the longitudinalmovement, or rotation, or both, of the tubular body it) of the tool andof the scraper blades 20, the springs 41 are urging the teeth 2-1against the foreign substances and the wall of the tubular string withsubstantial force, which force depends upon the strength of the helicalcompression springs. A large hearing area exists between the upper ends18 of the slots 16 and the upper ends 24 of the cutter blades in forcingthe scraper tool A downwardly through the well casing, and a largebearing area is also present between the trailing sides 17 of each slotand the trailing sides 23 of each blade for the transmission ofsubstantial torque in scraping the inner wall of the tubular string, asa result of rotating the apparatus. Such large areas and theirsubstantial inward extent insure the proper guiding of the scraperblades 20 in the body slots 16 and prevents their cocking or bindingtherewithin. They also insure a long and useful life of the body Ill ofthe tool and of the scraper blades 20 themselves. Despite the use ofcomparatively wide slots 16 through the tool body, its minimumcross-sectional area is still very large, resulting in the bodypossessing great strength, capable of safely withstanding extremelyheavy torques and longitudinal forces to which it might be subjected.Such large cross-sectional area is maintained despite the making of thescraper body of a comparatively small diameter to enable effective useof the apparatus A in tubing strings B of comparatively small diameter.The scraper apparatus is easily assembled land dismantled and hasrelatively few parts. Its manufacture is comparatively simple andeconomical, since the slots 16 through the body are readily formed andthe scraper blades 20 themselves are easily made through simple castinprocedures, requiring essentially no finishing, other than theapplication of hardfacing to the scraper teeth 21.

Although the scraper has been described in connection with running it inthe tubular string B on drill pipe D, or the like, it may, if desired,be used on a wire line or cable. As an example, the cable may beattached to suitable sinker bars and jars (not shown) which areconneoted to the upper end 12 of the body 10 of the tool, the sinkerbars and jars providing suflicient weight for forcing the scarping toolA downwardly through the casing. Such longitudinal movement in adownward direction will scrape the entire circumference of the wall ofthe tubular string B, in viewof the fact that the scraper teeth 21collectively cover a full 360 degree extent of the tubular string wall.

I claim:

1. In a tubular string scraper: a main body having means for attachmentto a running-in string and having a central longitudinal passagetherethrough; said body having opposed lateral slots extending inwardlyfrom its periphery and opening directly into said passage throughoutsubstantially the entire length of said slots; a tubular member in saidpassage extending across said slots for conducting drilling fluidthrough said body; opposed cutters slidable laterally in said slots,each cutter having inner portions extending partially around and astridesaid tubular member, said inner portions being slidable along the sidesof said slots; and means normally urging said cutters laterallyoutwardly.

2. In a tubular string scraper: a main body having means for attachmentto a running-in string and having a central longitudinalpassage'therethrough; said body having opposed lateral slots extendinginwardly from its periphery and opening directly into said passagethroughout substantially the entire length of said slots; a tubularmember in said passage extending across said slots for conductingdrilling fluid through said body; opposed cutters slidable laterally insaid slots and having inner portions extending partially around saidtubular member and slidable along the sides of said slots; and yieldablemeans extending transversely of said tubular member and on oppositesides thereof and disposed between and engaging said cutters for urgingsaid cutters laterally outwardly.

3. In a tubular string scraper: body means adapted for attachment to arunning-in string and having a longitudinal passage therethrough; saidbody means having opposed lateral slots extending inwardly from itsperiphery and directly opening into said passage; oppose cuttersslidable laterally in said slots and having inner portions confrontingeach other, said cutters having scraping teeth disposed at leastpartially longitudinally of said body means to scrape the tubular stringupon rotation of said body means; and yieldable means common to saidcutters and located between and engaging said confronting inner portionsof said cutters for urging said cutters laterally outwardly.

4. In a tubular string scraper: body means adapted for attachment to arunning-in string and having a longitudinal passage therethrough; saidbody means having opposed lateral slots extending inwardly from itsperiphery and opening into said passage; opposed cutters slidablelaterally in said slots, each cutter having external scraping teethextending at least partially longitudinally of said cutter to engage thewall of the tubular string along an extended length to scrape the sameupon rotation of said body means; and a plurality of springs betweensaid cutters, each spring engaging said opposed cutters to urge saidcutters in opposite directions laterally outwardly.

5. In a tubular string scraper: a main body adapted for attachment to arunning-in string and having a longitudinal passage therethrough; saidbody having opposed lateral slots extending inwardly from its peripheryand opening into said passage; a tubular member in said passageextending across said slots for conducting drilling fluid through saidbody; opposed cutters slidable laterally in said slots and having innerportions extending partially around said tubular member; and a pluralityof springs between said cutters, each spring engaging said opposedcutters to urge said cutters in opposite directions laterally outwardly.

6. In a tubular string scraper: a main body having means for attachmentto a running-in string and having a central longitudinal passagetherethrough; said body having opposed lateral slots extending inwardlyfrom its periphery and opening into said passage; a tubular member insaid passage extending across said slots for conducting dn'lling fluidthrough said body; cutters slidable laterally in said slots and havingconcave inner portions extending partially around said tubular memberand providing opposed inner side flanges on each of said cutters onopposite sides of an astride said tubular member, said flanges beingslidable along the sides of said slots; and yieldable means common tosaid cutters and located between and engaging said side flanges to urgesaid cutters laterally outwardly.

7. In a tubular string scraper: a main body adapted for attachment to arunning-in string and having a longitudinal passage therethrough; saidbody having opposed lateral slots extending inwardly from its peripheryand opening into said passage; a tubular member in said passageextending across said slots for conducting drilling fluid through saidbody; cutters slidable laterally in said slots and having concave innerportions extending partially around said tubular member and providingopposed inner side flanges on said cutters on opposite sides of saidtubular member; and a plurality of springs between 6 said opposed sideflanges on opposite sides of said tubular member, each spring engagingsaid opposed side flanges to urge said cutters in opposite directionslaterally outwardly.

8. In a tubular string scraper: a main body having means for attachmentto a running-in string and having a longitudinal passage therethrough;said body having opposed lateral slots extending inwardly from itsperiphery and opening directly into said passage, each slot beingdefined by top, bottom and side body walls, said passage opening intosaid opposed slots at said top and bottom walls of each slot; a tubularmember in said passage extending across said slots for conductingdrilling fluid through said body; cutters slidable laterally in saidslots, each cutter being engageable with all walls of its slot toprevent longitudinal and transverse movement of said cutter with respectto said body and being guided in its lateral movement by all Walls ofits slot, said cutters having scraping teeth disposed at least partiallylongitudinally of said body to scrape the tubular string upon rotationof said body; and means normally urging said cutters laterallyoutwardly.

9. In a tubular string scraper: a main body adapted for attachment to arunning-in string and having a longitudinal passage therethrough; saidbody having opposed lateral slots extending inwardly from its peripheryand opening directly into said passage, each slot being defined by top,bottom and-side body walls; a tubular member in said passage extendingacross said slots for conducting drilling fluid through said body;opposed cutters slidable laterally in said slots, each cutter beingengageable with all walls of its slot to prevent longitudinal andtransverse movement of said cutter with respect to said body and beingguided in its lateral movement by all walls of its slot; and a pluralityof springs between said cutters, each spring engaging said opposedcutters to urge said opposed cutters in opposite directions laterallyoutwardly.

It In a tubular string scraper: body means adapted for attachment to arunning-in string and having a longitudinal passage therethrough; saidbody means having opposed lateral slots extending inwardly from itsperiphery and opening directly into said passage, each slot beingdefined by top, bottom and side body walls, said passage opening intosaid opposed slots at said top and bottom walls of each slot; opposedcutters slidable laterally in said slots and having inner portionsconfronting each other, each cutter being engageable with all walls ofits slot to prevent longitudinal transverse movement of said cutter withrespect to said body means and being guided in its lateral movement byall walls of its slot, said cutters having scraping teeth disposed atleast partially longitudinally of said body to scrape the tubular stringupon rotation of said body; and yieldable means common to said cuttersand located between and engaging said confronting inner portions of saidcutters for urging said cutters laterally outwardly.

11. In a tubular string scraper: a main body having means for attachmentto a running-in string and having a longitudinal passage therethrough;said body having opposed lateral slots extending inwardly from itsperiphery and opening directly into said passage, each slot beingdefined by top, bottom and side body walls; a tubular member in saidpassage extending across said slot for conducting drilling fluid throughsaid body; opposed cutters slidable laterally in said slots, each cutterbeing engageable with all walls of its slot to prevent longitudinal andtransverse movement of said cutter with respect to said body and beingguided in its lateral movement by all walls of its slot, said cuttershaving concave inner portions extending partially around said tubularmember and providing opposed inner side flanges on each of said cutterson opposite sides of and astride said tubular member, said flanges beingslidable along the sides of said slots; and yieldable means common tosaid cutters and H I located between and engaging said side flanges tourge said cutters laterally outwardly.

12. In a tubular string scraper: a main body adapted for attachment to arunning-in string and having a longitudinal passage therethrough; saidbody having opposed lateral slots extending inwardly from its peripheryand opening into said passage, each slot being defined by top, bottomand side body walls; a tubular member in said passage extending acrosssaid slot for conducting drilling fluid through said body; cuttersslidable laterally in said slots, each cutter being engageable with allwalls of its slot to prevent longitudinal and transverse movement ofsaid cutter with respect to said body and being guided in its lateralmovement by all walls of its slot, said cutters having concave innerportions extending partially around said tubular member and providingopposed inner side flanges on said cutters on opposite sides of saidtubular member; and a plurality of springs between said opposed sideflanges on opposite sides of said tubular member, each spring engagingsaid opposed side flanges to urge said cutters in opposite directionslaterally outwardly.

13. In a tubular string scraper: a main body having means for attachmentto a running-in string and having a longitudinal passage therethrough;said body having a lateral slot extending inwardly from its peripheryand opening directly into said passage throughout substantially theentire length of said slot; a tubular member in said passage extendingacross said slot for conducting drilling fluid through said body; acutter slidable laterally in said slot and having inner portionsextending partially around and astride the tubular member, said innerportions being slidable along the sides of said slot; and means urgingsaid cutter laterally outwardly.

14. In a tubular string scraper: a main body having means for attachmentto a running-in string and having a slot opening through the peripheryof the body at diametrically opposite sides thereof; said body having acentral longitudinal passage therethrough opening into the upper andlower ends of said slot; a tubular member in said passage extendingacross said slot for conducting drilling fluid through said body;opposed cutters on diametrically opposite sides of said tubular memberand slidable laterally in said slot and adapted to project in oppositedirections beyond the periphery of said body, said cutters havingscraping teeth disposed at least partially longitudinally of said bodyto scrape the tubular string upon rotation of said body; and meansurging said cutters laterally outwardly of said body.

15. In a tubular string scraper: a main body having means for attachmentto a running-in string and having slot opening through the periphery ofthe body at diameto rically opposite sides thereof, said slot havingparallel side walls; said body having a central longitudinal passagetherethrough opening into the upper and lower ends of said slot; atubular member in said passage extending across said slot for conductingdrilling fluid through said body; opposed cutters on diametricallyopposite sides of said tubular member and slidable laterally in saidslot along its side walls and adapted to project in opposite directionsbeyond the periphery of said body, each cutter having inner portionsextending partially around and astride said tubular member, said innerportions being slidable along the sides of said slot; and means commonto said cutters and located between and engaging said inner portions forurging said cutters laterally outwardly.

16. In a tubular string scraper: a main body having means for attachmentto a running-in string and having a slot opening through the peripheryof the body at diametrically opposite sides thereof; said body having acentral longitudinal passage therethrough opening into the upper andlower ends of said slot; a tubular member in said passage extendingacross said slot for conducting drilling fluid through said body;opposed cutters on diametrically opposite sides of said tubular memberand slidable laterally in said slot and adapted to project in oppositedirections beyond the periphery of said body,

said cutters having scraping teeth disposed at least partiallylongitudinally of said body to scrape the tubular string upon rotationof said body; and yieldable means extending across the periphery of saidtubular member from a cutter on one side thereof to a cutter on theopposite side thereof and engaging said cutters to urge said cutters inopposite directions laterally outwardly of said body.

References Cited by the Examiner UNITED STATES PATENTS 1,011,384 12/11Sly 175291 1,372,894 3/21 Minton 175291 X 2,603,163 7/52 Nixon 1662122,693,239 11/54 Emanuel 166--173 2,713,913 7/55 Ragan 166-173 2,743,7815/56 Lane 166-17O X 2,836,251 5/58 Claypool et al 166-173 2,857,14110/58 Carpenter 166--l74 X 3,088,532 5/63 Kellner 166212 X 3,123,1623/64 Rowley 166-212 FOREIGN PATENTS 106,451 1/ 99 Germany.

CHARLES E. OCONNELL, Primary Examiner.

BENJAMIN HERSH, Examiner,

1. IN A TUBULAR STRING SCRAPER: A MAIN BODY HAVING MEANS FOR ATTACHMENTTO A RUNNING-IN STRING AND HAVING A CENTRAL LONGITUDINAL PASSAGETHERETHROUGH; SAID BODY HAVING OPPOSED LATERAL SLOTS EXTENDING INWARDLYFROM ITS PERIPHERY AND OPENING DIRECTLY INTO SAID PASSAGE THROUGHOUTSUBSTANTIALLY THE ENTIRE LENGTH OF SAID SLOTS; A TUBULAR MEMBER IN SAIDPASSAGE EXTENDING ACROSS SAID SLOTS FOR CONDUCTING DRILLING FLUIDTHROUGH SAID BODY; OPPOSED CUTTERS SLIDABLE LATERALLY IN SAID SLOTS,EACH CUTTER HAVING INNER PORTIONS EXTENDING PARTIALLY AROUND AND ASTRIDESAID TUBULAR MEMBER, SAID INNER PORTIONS BEING SLIDABLE ALONG